Quantitative analysis of the spinal cord motoneuron under chronic compression: an experimental observation in the mouse

We investigated quantitative changes in spinal cord motoneurons following chronic compression using a mouse model of cervical cord compression. Twenty-five tiptoe-walking Yoshimura (twy) mice with calcified mass lesions compressing the spinal cord posterolaterally at the C1–C2 vertebral levels were compared with five Institute of Cancer Research (ICR) mice that served as controls. Spinal cord motoneurons in the anterior grey horn between the C1 and C3 spinal cord segments were Nissl-stained and counted topographically and then analysed in relation to the extent of spinal cord compression. The number of motoneurons in C1–C3 spinal cord segments decreased significantly with a linear correlation with the transverse area of the spinal cord when the cord was compressed to 50–70% of control values. A significant reduction in the number of motoneurons occurred at the C2–C3 spinal cord segment compressed at the C1–C2 vertebral level. In contrast, at the level rostral to the C1 vertebra, the number of motoneurons increased significantly in proportion to the magnitude of compression. The current study demonstrates that a number of neurons, morphologically consistent with anterior horn cells, were observed at a rostral site absolutely free of external compression where no such cells normally exist.     

Decreased serum levels of epidermal growth factor in adult subjects with high-functioning autism.

BACKGROUND: The neurobiological basis for autism remains poorly understood. Given the role of growth factors in brain development, we hypothesized that epidermal growth factor (EGF) may play a role in the pathophysiology of autism. In this study, we examined whether serum levels of EGF are altered in adult subjects with high-functioning autism. METHODS: We measured serum levels of EGF in the 17 male subjects with high-functioning autism and 18 age-matched healthy male subjects. RESULTS: The serum levels of EGF in the subjects with high-functioning autism (72.4 +/- 102.8 pg/mL [mean +/- SD]) were significantly lower (Mann-Whitney U = 22.0, p < .001) than those of normal control subjects (322.3 +/- 122.0 pg/mL [mean +/- SD]). However, there were no correlations between serum EGF levels and clinical variables in the subjects with autism. CONCLUSIONS: This study suggests that decreased levels of EGF might be implicated in the pathophysiology of high-functioning autism.     

Mutational analysis of CACNA1G in idiopathic generalized epilepsy. Mutation in brief #962. Online

Recent studies have strongly implicated low voltage-activated/T-type calcium channels (T-channels) in the etiology of epilepsy. Here, we report the results of a mutational analysis of the CACNA1G gene, encoding the T-channel Ca(V)3.1/(1G) subunit, using a cohort of 123 mostly Japanese and Hispanic patients with idiopathic generalized epilepsies (IGE) and 360 healthy control individuals. We found 13 variants, including five which involved amino acid substitutions. One variant, c.1709C>T (Ala570Val), is present in a sporadic case of juvenile myoclonic epilepsy (JME) with early childhood absence and astatic seizures, but was not found in control samples. Another variant, c.3265G>T (Ala1089Ser), was observed in three family members affected with JME, and also in one control individual. Two JME patients and three control individuals harbored a third variant, c.2968G>A (Asp980Asn). Although not statistically significant, slightly faster inactivation decay rates were observed in some mutant channels. Our collective findings flag CACNA1G as a potential susceptibility locus for IGE subsyndromes that warrants closer investigation.     

Comparison of the effects of in-vivo thermal ablation of pig liver by microwave and radiofrequency coagulation

Microwave and radiofrequency coagulation is frequently used for the treatment of hepatic tumors. However, differences between these types of therapy have not been clearly demonstrated so far. We performed both types of thermal ablative treatment on pig liver, and compared the size and shape of the coagulated areas produced. The effects of combining both treatments and interrupting hepatic blood flow were also evaluated. The liver of an anesthetized pig was thermally coagulated, with or without interruption of hepatic blood flow, using a needle electrode at 40 W for 150 s with 2450-MHz microwaves and/or with a 460-kHz radiofrequency current. The diameters of the coagulated areas in the liver were 20 ± 3 mm (mean ± SD; n = 4) after microwave coagulation and 28 ± 3 mm following radiofrequency coagulation when blood flow was not interrupted, whereas they were 31 ± 2 mm and 37 ± 3 mm, respectively, when blood flow was interrupted. When these treatments were combined sequentially, the diameters of the lesions were 43 ± 3 mm and 29 ± 2 mm with and without blood flow interruption, respectively. The ellipticity of the coagulated area, as measured by the largest-to-smallest ratio of its diameters, was 2.3 ± 0.4 after microwave coagulation and 1.1 ± 0.1 following radiofrequency coagulation. We conclude that radiofrequency coagulation produces a larger and more spherical coagulated area in the liver (P < 0.01) than does microwave coagulation. The lesion becomes larger (P < 0.05) with both treatments when hepatic blood flow is interrupted during the treatment. The sequential combination of these treatments produces a much larger lesion (P < 0.05) than that produced by either treatment alone.     

Changes in Brain Thyrotropin-Releasing Hormone (TRH) of El Mice

The present study showed that DN-1417 had a dose-dependent anticonvulsant activity on El mouse seizure. This finding is consistent with other reports using the kindling model of epilepsy. Since both the El mouse and kindling preparations have been regarded as complex partial seizure with secondary generalization, endogenous brain TRH, as well as exogenous TRH, may act as an anticonvulsant substance to such a seizure type of epilepsy. Moreover, this study showed IR-TRH of the El mouse changed significantly in the striatum or hippocampus genetically or postictally without a change in the TRH receptor binding. A transient decrease in hippocampal IR-TRH after convulsion shown in this study may suggest an increased release of TRH during and after the seizure.
Further studies are required to clarify the relationship between a change in the brain TRH system and seizure susceptibility in the El mouse.     

Caffeine rapidly decreases potassium conductance of dissociated outer hair cells of guinea-pig cochlea

The effects of caffeine on the outer hair cells (OHCs) freshly dissociated from guinea-pig cochlea were investigated with the whole-cell patch-clamp technique, in both the conventional and the nystatin perforated patch-clamp configurations under voltage-clamp condition. Application of caffeine (> 1 mM for 10–30 s) induced an inward current (I_caffeine) with decrease of conductance in a dose-dependent manner at a holding potential (V_H) of −60 mV. The reversal potential ofI_caffeine (E_caffeine) was close to the K⁺ equilibrium potential. TheI_caffeine was not affected by Ca²⁺-free external solution. The internal perfusion of the Ca²⁺ chelator BAPTA had no effect onI_caffeine. TheI_caffeine was not modulated by the external application of H-8 or staurosporine and by the internal perfusion of GDP-βS. The amplitude ofI_caffeine was the largest at the basal region of OHCs when caffeine was locally applied by the ‘puffer’ method. These results suggest that caffeine induces a decrease in membrane potassium conductance of the OHCs mainly at the basal region without mediating the intracellular signaling pathway.     

Occurrence of human papillomavirus types 16 and 18 DNA in cervical carcinomas from Japan: age of patients and histological type of carcinomas

We have detected by DNA hybridization human papillomavirus (HPV) types 16 and 18 DNA sequences in 19 and 3, respectively, out of 56 cervical carcinomas from Japan. Eighteen out of 19 HPV 16-positive specimens were from squamous cell carcinomas, whereas the three HPV 18-positive specimens were from a squamous cell carcinoma (1/50), an adenosquamous carcinoma (1/3), and an adenocarcinoma (1/3). The occurrence of HPV 16 DNA decreased in patients over 60 years old (less than or equal to 60 years, 15/34 (44%); 60 years less than, 4/22 (18%)) (P less than 0.05).